1. Field of the Invention
The present invention generally relates to an electronic card connector, and in particular to an electronic card connector having a stand-off device and an adapter board for connecting the connector to a circuit board.
2. The Prior Art
As computer technology advances, the dimension of a computer is becoming increasingly smaller while the functional performance thereof is improving. The computer is often equipped with an electronic card connector for releasably connecting an electronic card, such as a memory card, for expanding the functional capabilities of the computer. Examples of conventional electronic card connectors are disclosed in Taiwan patent application Nos. 83218076 and 85219426.
FIG. 1A of the attached drawings shows a conventional electronic card connector wherein two connectors 156, 157 are stacked on each other and supported on a circuit board 151. Stand-off members 162 are provided between the connectors 156, 157 and the circuit board 151 for spacing the connectors 156, 157 a predetermined distance from the circuit board 151. The upper connector 156 has contact terminals 158 soldered to an adapter board 154 that is connected to the circuit board 151 by means of a card edge connector 153. Similarly, the lower connector 157 has contact terminals 159 soldered to another adapter board 155 that is connected to the circuit board 151 by means of a card edge connector 152.
Such an arrangement, however, presents several disadvantages. For example, each adapter board 154, 155 has two rows of terminal receiving holes that are generally aligned with each other as shown in FIG. 1B. Such an arrangement causes traces 166 of the upper row terminal receiving holes to extend in a non-straight path in order to avoid overlapping the lower row terminal receiving holes. The greater the number of terminal receiving holes defined in the adapter board, the more complicated the layout of the traces becomes. Furthermore, such an arrangement requires the upper and lower connectors to have individual adapter boards. Thus, manufacture of the electronic card connector is complicated and the overall dimension of the electronic card connector is increased.
Furthermore, the sole function of the stand-off members 162 of the conventional electronic card connector is to space the connectors 156, 157 from the circuit board 151. Additional fasteners are needed to secure the connectors 156, 157 to the circuit board.
It is thus desirable to have an electronic card connector that overcomes the above discussed problems of the prior art.